Fatal pneumocystis carinii pneumonia in AIDS : A case report.

ABSTRACT

The human lower respiratory system begins to form about day 26-27 after conception, and is first indicated by a median larngotracheal groove in the caudal and of the ventral wall of the larynx, trachea, bronchi and the pulmonary lining epithelium. The connective tissue, the cartilage and the smooth muscle of these structures develop from the splanchnic mesoderm surrounding the foregut. In studying the development of the respiratory system at the Department of Anatomy, Siriraj Hospital, Medical students should trace the serial section of 10 mm and 15 mm pig embryos. In doing this, they be able to observe the layngotracheal groove at the floor of the pharynx and when, tracing the sections caudally, they will be able to observe the trachea, esophagus and the bifurcation of the trachea to from primary bronchi as well as the smaller branches of bronchi. The present study attempts to show the development of the respiratory system of rat embryos in order to find the most suitable stage which can be used as a laboratory model for use by students. A 6 mm rat embryo can be used instead of a pig embryo for studying the development of the respiratory system, if pig embryos are not available.